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#include<iostream>
using namespace std; 

int main(){
    int k; cin>>k; 
    string binar; 

    if (k == 1){
        cout<<2<<endl; 
        cout<<2<<' '<<-1<<endl;
        cout<<-1<<' '<<-1<<endl; 
        return 0; 
    }
    while (k > 0){
        if (k%2 == 0)
            binar += '0';
        else 
            binar += '1';
        k /= 2; 
    }
    int w = (binar.size()-1)*3 + 1; 
    int G[w+1][2]; 

    for (int i = 1; i <= w; i++){
        if (i%3 == 1){
            G[i][0] = i+1; 
            G[i][1] = i+2; 
        }
        else if (i%3 == 0){
            G[i][0] = i+1;
            G[i][1] = -1; 
        }
        else {
            G[i][0] = i+2; 
            if (binar[i/3] == 0)
                G[i][1] = -1; 
            else 
                G[i][1] = w-2; 
        }
    }
    G[w][0] = -1; 
    G[w][1] = -1; 
    G[w-2][1] = -1; 
    //cout<<binar<<' '<<binar.size()<<' '<<binar[binar.size()-1]<<endl; 
    if (binar[binar.size()-1] == '1')
        G[w-1][1] = w-2; 
    //cout<<G[w-1][1]<<endl; 
    cout<<w<<endl; 
    for (int i = 1; i <= w; i++){
        cout<<G[i][0]<<' '<<G[i][1]<<endl; 
    }
}